Sesquiterpene Lactones from Anthemis melanolepis and Their Antibacterial and Cytotoxic Activities. Prediction of Their Pharmacokinetic Profile

Nine sesquiterpene lactones, anthemin A (1), 1α-hydroxydeacetylirinol-4α,5β-epoxide (2), anthemin C (3), tatridin A (4), 1-epi-tatridin B (5), anthemin B (6), 6-deacetyl-β-cyclopyrethrosin (7), elegalactone A (8), and 1β,4α,6α-trihydroxyeudesm-11-en-8α-12-olide (9), were isolated from the aerial parts of A. melanolepis in addition to eight known flavonoids and three phenolic acids. Compounds 1, 3, and 6 are new natural products. The structures of the compounds were deduced by spectroscopic methods. The in vitro antimicrobial potential of the isolated sesquiterpene lactones against four Gram-positive and five Gram-negative bacteria and one fungus was evaluated using the microdilution method, and their in vitro cytotoxic activity was determined against a panel of human tumor cell lines. Furthermore, the pharmacokinetic profile of the sesquiterpene lactones was investigated using computational methods.